Trichromatic photographic apparatus.



P. E. IVES.

TRICHROMATIC PHOTOGRAPHIG APPARATUS.

APLIOATION FILED '00T.18, 1909.

Patented Jan. 10, 1911.

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P. E. IVES. TEIGHROMATIG PEOTOGBAPHIG APPARATUS.

APPLIOATIN FILED 00T.18, 1909.

Patented Jan. 10,1911.

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FREDERIC E. IVES, 0E WEEHAWKEN, NEW JERSEY.

TRICHROMATIC PHOTOGRAPHIC APPARATUS.

Specification of Letters Patent.

Application led October 18, 1909. Serial No. 523,186.

three separate color` record negatives re-v quired for certain forms of the trichromatic process of photography.

My invention relates especially tol that method in which the three sensitive plates, each corresponding to its respective color sensation, are combined in the form of a pack.

In the accompanying drawings-Figure l is a vertical longitudinal section of a sensitive plate pack and camera constructed in accordance with my invention, the parts occupying the positions assumed by them when the plate holder is first applied to the camera; Fig. 2 is a similar view representing the relation of the parts to one another when the exposure is being made; Figs. 3

and 4 are vertical lon itudinal sections illustratin certain modi cations of my invention; ig. 5 vis a transverse section through the plate holder, showingx the plates in the e exposure is being made; Figs. 6, 7, 8, and 9 are views illustrating d1'erent forms of sensitive plate pack .in accordance with my invention, Figs. 6, 7 and 8 being on an enlarged scale, Aand Fig. 10 is a transverse section of the lens tube illustrating a special form of lens aperture.

Referring in theirst instance to Figs. 1 and 2 of the drawings, 1-represents the casing of the camera, and 2 is the objective lens which ma be provided with focus'in attachments o an ordinary character. sliding base-plate 3, located within the camera, carries a lens 4, and a transparent reflector 5 disposed at an angle of 45. A plate-holder 6 of ordinary construction,pro vided witha sliding shutter 7 is tted to an aperture in the 'top ofthe camera in any convenient way. This plate-holder carries the sensitive plate pack which comprises the three sensitive plates` 9, l0 and 11, the green sensitive plate 9 being at the back of the holder with its film side down, the blue sensitive plate 10 being disposed with its film side up and in contact with the yfilm side of the green sensitive plate 9, and the red sensitive plate 11 bei also disposed film side upl with its film 1n contact with the back/of the blue sensitive plate 10.

By preference, the green sensitive plate 9 has a light proof backing 12 and the red sensitive plate 11 has asimilar light proof backing l13, whereby the sensitive surfaces are all shielded from exposure to light when 'putting the pack in or taking it out of the holder and during .the transportation of the pack from place to place. Strips 14 bind together the blue and green sensitive plates at one edge, and the three plates at the opposite edge, the latter strip also providing a flexible hinge 15 for the face plate 11, which is narrower than the other plates, the front and side edges of said plate 11 being, therefore, free from confinement but said plate being normally held in its proper relation to the other plates by the sliding shut-ter 7 of the plate-holder after the pack has been inserted in the-holder. The plates 9 and 10 may therefore be said to constitute one member of the pack and the plate 11 anotherr member hinged to the first.

The side portions of the `member comprising the plates 9 and 10, when the pack is laid in the holder, rest u on suitable ledges 6*i therein, and may be he d against the same by a suitable spring 6b onv the back plate of the holder as shown in Fig. 5.

Either before ,or after the ap licationof the plate-holder to the camera t e slide 3 is drawn forward by any suitable means, as for instance, by a rod 16 passing through `an Patented Jan. l1o, 1911. y

opening in the front of the camera, whereby,

when the sliding shutter 7 of the plate holder is withdrawn, the 'plate 11 will drop down into contact with y the back of the camera, as shown in Fig. 2, and the slide 3 'is then vpushed inward so as to bring the lens 4 into proper relation to the objectivelens 2 and locate the diagonally disposed transparent mirror 5 below the p ates 9 and 10 containedin the holder, and in front of the plate 11 which lies against the back of the camera.

After th'e exposure has been made the slide 3 is drawn forward and the .plate 11 can then -be swung u into its proper relation tothe other member of the pack either by means of an arm 17 located at theback .of the camera and' carried by a rock shaft 19 accessible from the outside of thev camera, or by tilting the camera so as cause said plate loo llto swing by gravity to its proper position in the holder, the sliding shutter 7 being then re-applied to the holder so as to properly retaln the plates therein.

The trans arent reiector 5 serves to difvidej the lig t rays in order to form twol separate images, one for the blue and green sensitive plates in the holder and the other for the red sensitive theret and this transparent reector may be o a red color, in order to render unnecessary t-he application of any color screen to the red sensitive plate 11.

lThe purpose of the lens 4 is to approximately parallelize the diverging cone of rays from the objective lens 2, and thereby correct or minimize the distortion incident to refraction at various angles through an inclined transparent reflector and also to equalize the color" absorption and percentage of refiection from top to bottom of the reector.

mayv use a diaphragm strip 24 for In the absence of this lens there would, be cause of the dierent angles of incidence, be considerably more reflected li ht and correspondingly less transmitted llght toward the edge of therefiector farthest removed from the objective lens.

In order to prevent any light from the lens aperture from reaching, directly, any part of the'faces of the horizontal plates I partially shielding the lens 4.

The relation of the parts asshown in Figs.

l to 4 involves the loss of a small portion of each plate 9 and 10, by reason of the reiector 5 not extending to the edges of these plates.

With the plates hinged as shown, the

'image at the upper ortion of the plate 11 would also be imper ect because of the cutting off of light by the diaphragm strip 24. In order to minimize this loss, without proportionately increasing the time of exposure, I prefer to employ a horizontally elongated lens aperture, as shown in Fig. 10. The vertical position of the plate 11, however,and its relation to the image rojected by the lens is dependent upon tle Width of the hinge strip whereby said plate is connected to the plates 9 and 10.

The sensitive plates may be prepared in accordance with my Letters Patent N o.

927,244, dated July 6th, v1909, although perfect transparency of the blue sensitive plate is not absolutely necessary.

The compensating lens 4 so supplements the object-ive lens 2 as to virtually shorten its focus, making it substantially equivalent to a lens of the same actual aperture and of focal length equal to the Idistance from the objective lens to the compensating lens when adaptedto form sharp images on the sensitive plates. The objective lens 2 must therefore be of longer focus to occupy a given position when the compensating lens is in place than it would be in the absence of such complate at a right AangleV pensating lens. It is possible, however, to substitute for t-he combination of objective lens and compensating lens shown in Figs. l`

and 2 a single achromatic lens of the dlameter of the image of the object to be photographed, with a diaphragm placed at "its focal length in front of it, squch construction being illustrated in Fig. 3, in which 20 represents such achromatic lens and 21 the diaphragm. This camera, however, would be 'shown in Fig. 4, the plate holder is at the rear end of the camera and retains the red sensitive late 11, preferably by frictional Contact ofp the 'sides of the plate holder with the edges of the flute, the member comprising the blue and green sensitive plates dropping down onto the bottom of the camera 1n order to el'ct their exposure, onal transparent mirror 5 occup ing a reverse angle to that illustrated in igs. 1 and 2. The separation and re-assembling of the members of the pack may be effected either by tilting the camera or by means of a swinging arm similar to that shown in Fig. l, if deslred. y

All of the plates may, if desired, be of the same size, as shown in Fig. 7, the member comprising the blue and green sensitive plates being retained in the holder by frictional contact of the walls of the latter with the edges of the plates.

A preferable method of constructing the l and the diagpack is to 'bind together the back and intermediate plates\9 and 10, -as 'shown at 22 in Figs. 8 and 9, and to bind together the edges of the back and face plates at the other side of the pack, as shown at 23 in said gures, as this -not only provides a hinged connection between the member comprising the plate 11 and the member comdprising the plates 9 and 10 but also a hinge connection between the latter plates, and thus ermits the plates 'to s read out side by side, ace up, when the `pac is removed from the holder, the three plates being placed in the developing tray in this position and the connecting strips being loosened by the developing'solution so as to render 1t unnecessary to cut said strips before proceeding with the development of the plates.

I claim:

1. A trichromatic process sensitive plate pack comprising three color sensitive plates constituting members which are, normally held in overlying relation by a binding.stilp exi e at one ved e, said binding strip being whereby 1t constitutes a hinge which permits one member of the pack to swing outwardly in respect to the other.

2. A trichromatic process sensitive plate pack comprising three color sensitive plates constituting members whichv are normally held in overlying relation by a bindin strip at one edge, said binding strip being exible whereby it constitutes a hinge which permits one member of the pack to swing outwardly in respect to the other, one member of the pack being of lesser dimensions than the other whereby the latter may engage with a retainer without restricting the swinging movement of the first member.

3. A trichromatic process sensitive plate pack comprising three color sensitive plates constituting members held normally in overlying relation by binding strips so as to be conveniently handled as a unit, and having at one edge a flexible binding strip which constitutes a hinge whereby one meml ber of the pack may swing outwardly in respect to the other.

4. A trichromatic process 'sensitive plate pack comprising three color sensitive plates constituting members held normally 1n overlying relation by binding strips so as to be conveniently handled as a unit, and having at one edge a flexible binding strip which constitutes a hinge whereby one member of the pack may swing outwardly in respect to the other, one member of the pack being of lesser dimensions than the other whereby the latter member can be retained by engagement with the holder without interfermg with 'the swinging movement of the rst member.

5. A trichromatic/process sensitive plate pack comprising three color sensitive plates constituting members which are normally held in overlyingV relation b -means of'a binding strip at onev edge, sai binding strip being flexible so las to constitute a hinge whereby -one member can swing in respect to the other, in combination with a .holdel` for said pack having portions for engaging and retaining one member of the same while permitting the swinging movementI of the other member.

6. A trichromatic process sensitive plate pack comprising three color sensitive plates constituting members which are normally held in overlying relation by -means of a binding strip at one edge, said binding strip being flexible so as to constitute a hinge whereby one member of the pack can sWin' in respect to the other,`said swinging member being of lesser dimensions than thef other, in combination with a holder for said plate pack having means Vfor overlapping and retaining the larger member of the ack while permitting swinging movement o the smaller member.

7. A trichromatic process sensitive'plate packcomprising three color sensitive plates vone edge so t at said and edge bindings, one of the latter constituting a flexible hinge for connecting one of the plates to another. i A l 8. A trichromatichproeess sensitive plate pack comprising three color sensitive 4plates and edge bindings, which constitute flexible hinges for connecting lthe plates to one another.

9. A trichromatic Aprocess sensitivel plate pack comprising three color-sensitive plates, and front and rear light-proof backings, one of said color-sensitive plates and a backing being to ether hin ed to the others at. ate and backing can be swung outwardly rom the other plates and their backing.

' 10. A trichromatic process sensitive-plate pack comprisin three plates sensitive respectively to re green and blue color sensal tion and hinged together at their edges so that they can be spread out flat in series or can be folded directly one over another. 11. A trichromatic process sensitive-plate pack comprising three plates sensitive respectively to red, green and blue color sensation and hin ed together at their edges so that they can spread out flat in series with their sensitive faces up or can befolded' directly one over another.

l2. The combination of a trichromatic sensitive-plate pack comprising membersA pivotally connected to one another whereby one of said members can be caused to overlie the other or can im turned at an angle thereto, with a camera having a lens, a transparent reflector separate from the plate ack, and means for movably mounting s ai re- Hector in the camera whereby it can be interposed atan angle of forty-five degrees ibetween the separated members of the plate pack or can be removed from such posltion so as to permit the folding of the hin ed member of the plate pack over the ot er member of the same.

13. The combination of a 4trichromatic sensitive-plate pack comprising members pivoted together whereby one can be caused to overlie the other or can be turned at an aggle thereto, with a camera having a mova e slide therein provided witha transparent reflector disposed at an angle thereon, whereby'it can be inserted between/the separated members of the plate pack or can be withdrawn from such position.

14. The combination of a trichromatic -sensitive-plate pack 'comprising members,

15. In a camera for trichroma-tic process negative makin ,the combination of an objective lens, a p ate holder, a lm pack comprising members hinged together so that one can assume an angular relation to the other, an inclined transparent mirror, a compensating lens interposed between said mirror an the objective lens, and a movable mountin for said mirror and compensating lens Wereby both are simultaneously adjusted to operative or inoperative posi'- tion in respect t0 the film pack, the mirror,

@admi when in operative relation with said pack, serving to separate the rays and direct some of .them to che member of the pack and 15 others to the other member of the pack.

In testimony whereo; I havesigned my name to this specication, in the presence of tWo` subscribmg witnesses.

FREDERIC E. IVES. Witnesses:

HAMILTON D. TURNER, KATE A.' BADLE. 

